UNIVERSITY PARK, Pa. -- Snow cover that reached a depth of 3 feet earlier this month in much of the northcentral region, covered by a thick crust of ice from freezing rain -- along with weeks of unrelenting frigid temperatures -- have created a crisis for deer in parts of Pennsylvania, according to wildlife scientists in Penn State's College of Agricultural Sciences. But as brutal as conditions have been, they agree that March weather will determine the fate of many whitetails.

"The jury is still out on the winter," says Duane Diefenbach, adjunct assistant professor of wildlife. He has watched deer struggle with the snow cover in recent weeks while involved in deer research done by the School of Forest Resources. "We are still capturing and tagging deer in the final year of a three-year buck study, and we have seen that deer are just not moving. They haven't been coming in to our baits.

"The snow conditions have been absolutely awful," he adds. "This crusted snow makes it so difficult for deer to walk. The crust supports them initially then collapses under their weight. It takes a tremendous amount of energy for them to wade through it. Deer are better off not moving much, just staying still and not expending energy. Trying to find food would cost them more energy than they would gain from eating." Well north of Pennsylvania, in the northern part of the white-tailed deer's range, March is widely considered the "make or break month," according to Diefenbach. Here in the Keystone State, where winter thaws that often occur in January and February give wildlife a break to find food, it is usually not as significant. But this year is the exception. "If the weather stays cold and we get more snow and ice, we have the potential for significant winter mortality of deer," he says. "If the weather breaks next month, most of the animals will be all right. It has been a hard winter, and by now they have used most of their fat reserves. It is what comes next that will tell the tale."

But hard as this winter has seemed, it is not even close to being a record breaker, notes Bryan Swistock, extension water resources specialist and a tracker of Pennsylvania weather data. "It has been colder than average, but nowhere near the coldest," he says. "This winter will be in the top 10 ever for snowfall -- we have a pretty deep snow pack built up -- but it has been the ice on top of the snow that has been unusual."

That ice is what most concerns Walter Tzilkowski, associate professor of wildlife science. "Deer are more prone to slip and fall, and break a bone," he says. "I don't think many people really know how bad the winter will be right now. We won't be sure until people can get into the forest in March or April and count deer carcasses."

Pennsylvania Game Commission biologist Bill Palmer characterized February snow conditions as "horrible." "But you don't have to worry about big deer, they are kind of built by nature to survive winter," he says. "What we will lose will be the young, small deer. They just don't have the fat reserves. This likely will not go down in history as a terribly severe winter, but it will be severe enough to kill some animals. The deep, ice-encrusted snow cover is bad enough to cause mortality." Adult deer are well equipped to handle most winters, agrees Gary San Julian, professor of wildlife resources. But he points out that the ice is the wildcard. "Deer are adept at finding places to avoid deep snow and lessen the affects of severe cold," he says. "They will congregate and try to get out of wind and snow in protected places such as hemlock groves, which gives them a thermal advantage. But ice causes them serious problems trying to find food. They have trouble moving -- both slipping and falling and breaking through the crust, and being forced to plow through the deep snow. Deer try to paw down to vegetation they can eat. By this late in a hard winter, most of the easy-to-get food is already eaten."

But he has faith in natural systems finding equilibrium. "As a biologist, I have confidence that Mother Nature has a way of bringing populations into line," he says. "When you look at the big picture, it all seems to balance out. Previous to last year, we had a number of easy winters in a row when wildlife fared very well. Pennsylvania is not like New England where there are annual significant winter wildlife mortality events, but during a winter like this one, it may occur. The next few weeks will tell the tale."

###

EDITORS: Contact Duane Diefenbach at 814 865 4511 or by e-mail at ddiefenbach@psu.edu.

Jeff Mulhollem Office 814-863-2719 FAX 814-863-9877